Thuban/Model/layer.py

# Copyright (c) 2001, 2002 by Intevation GmbH
# Authors:
# Bernhard Herzog <[email protected]>
# Jonathan Coles <[email protected]>
#
# This program is free software under the GPL (>=v2)
# Read the file COPYING coming with Thuban for details.

__version__ = "$Revision$"

import os
from math import log, ceil

from Thuban import _

import shapelib, shptree

from messages import LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \
     LAYER_VISIBILITY_CHANGED

from color import Color

import classification

from table import Table

from base import TitledObject, Modifiable

class Shape:

    """Represent one shape"""

    def __init__(self, points):
        self.points = points
        #self.compute_bbox()

    def compute_bbox(self):
        xs = []
        ys = []
        for x, y in self.points:
            xs.append(x)
            ys.append(y)
        self.llx = min(xs)
        self.lly = min(ys)
        self.urx = max(xs)
        self.ury = max(ys)

    def Points(self):
        return self.points


# Shape type constants
SHAPETYPE_POLYGON = "polygon"
SHAPETYPE_ARC = "arc"
SHAPETYPE_POINT = "point"

# mapping from shapelib shapetype constants to our constants
shapelib_shapetypes = {shapelib.SHPT_POLYGON: SHAPETYPE_POLYGON,
                       shapelib.SHPT_ARC: SHAPETYPE_ARC,
                       shapelib.SHPT_POINT: SHAPETYPE_POINT}

shapetype_names = {SHAPETYPE_POINT: "Point",
                   SHAPETYPE_ARC: "Arc",
                   SHAPETYPE_POLYGON: "Polygon"}

class BaseLayer(TitledObject, Modifiable):

    """Base class for the layers."""

    def __init__(self, title, visible = 1):
        """Initialize the layer.

        title -- the title
        visible -- boolean. If true the layer is visible.
        """
        TitledObject.__init__(self, title)
        Modifiable.__init__(self)
        self.visible = visible

    def Visible(self):
        """Return true if layer is visible"""
        return self.visible

    def SetVisible(self, visible):
        """Set the layer's visibility."""
        self.visible = visible
        self.issue(LAYER_VISIBILITY_CHANGED, self)


class Layer(BaseLayer):

    """Represent the information of one geodata file (currently a shapefile)

    All children of the layer have the same type.

    A layer has fill and stroke colors. Colors should be instances of
    Color. They can also be None, indicating no fill or no stroke.

    The layer objects send the following events, all of which have the
    layer object as parameter:

        TITLE_CHANGED -- The title has changed.
        LAYER_PROJECTION_CHANGED -- the projection has changed.
        LAYER_LEGEND_CHANGED -- the fill or stroke attributes have changed

    """

    def __init__(self, title, filename, projection = None,
                 fill = Color.None, 
                 stroke = Color.Black, 
                 lineWidth = 1, 
                 visible = 1):
        """Initialize the layer.

        title -- the title
        filename -- the name of the shapefile
        projection -- the projection object. Its Inverse method is
               assumed to map the layer's coordinates to lat/long
               coordinates
        fill -- the fill color or Color.None if the shapes are not filled
        stroke -- the stroke color or Color.None if the shapes are not stroked
        visible -- boolean. If true the layer is visible.

        colors are expected to be instances of Color class
        """
        BaseLayer.__init__(self, title, visible = visible)

        # Make the filename absolute. The filename will be
        # interpreted relative to that anyway, but when saving a
        # session we need to compare absolute paths and it's usually
        # safer to always work with absolute paths.
        self.filename = os.path.abspath(filename)

        self.projection = projection
        self.shapefile = None
        self.shapetree = None
        self.open_shapefile()
        # shapetable is the table associated with the shapefile, while
        # table is the default table used to look up attributes for
        # display
        self.shapetable = Table(filename)
        self.table = self.shapetable

        #
        # this is really important so that when the classification class
        # tries to set its parent layer the variable will exist
        #
        self.__classification = None 


        self.SetClassification(None)

        self.__classification.SetDefaultLineColor(stroke)
        self.__classification.SetDefaultLineWidth(lineWidth)
        self.__classification.SetDefaultFill(fill)
        self.__classification.SetLayer(self)

        self.UnsetModified()

    def open_shapefile(self):
        if self.shapefile is None:
            self.shapefile = shapelib.ShapeFile(self.filename)
            numshapes, shapetype, mins, maxs = self.shapefile.info()
            self.numshapes = numshapes
            self.shapetype = shapelib_shapetypes[shapetype]

            # if there are shapes, set the bbox accordinly. Otherwise
            # set it to None.
            if self.numshapes:
                self.bbox = mins[:2] + maxs[:2]
            else:
                self.bbox = None

            # estimate a good depth for the quad tree. Each depth
            # multiplies the number of nodes by four, therefore we
            # basically take the base 4 logarithm of the number of
            # shapes.
            if self.numshapes < 4:
                maxdepth = 1
            else:
                maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))

            self.shapetree = shptree.SHPTree(self.shapefile.cobject(), 2,
                                             maxdepth)

    def Destroy(self):
        BaseLayer.Destroy(self)
        if self.shapefile is not None:
            self.shapefile.close()
            self.shapefile = None
            self.shapetree = None
        self.table.Destroy()

    def BoundingBox(self):
        """Return the layer's bounding box in the intrinsic coordinate system.

        If the layer has no shapes, return None.
        """
        # The bbox will be set by open_shapefile just as we need it
        # here.
        self.open_shapefile()
        return self.bbox

    def LatLongBoundingBox(self):
        """Return the layer's bounding box in lat/long coordinates.

        Return None, if the layer doesn't contain any shapes.
        """
        bbox = self.BoundingBox()
        if bbox is not None:
            llx, lly, urx, ury = bbox
            if self.projection is not None:
                llx, lly = self.projection.Inverse(llx, lly)
                urx, ury = self.projection.Inverse(urx, ury)
            return llx, lly, urx, ury
        else:
            return None

    def GetFieldType(self, fieldName):
        self.open_shapefile()
        info = self.table.field_info_by_name(fieldName)
        if info is not None:
            return info[0]
        else:
            return None

    def NumShapes(self):
        """Return the number of shapes in the layer"""
        self.open_shapefile()
        return self.numshapes

    def ShapeType(self):
        """Return the type of the shapes in the layer.
        This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.
        """
        self.open_shapefile()
        return self.shapetype

    def Shape(self, index):
        """Return the shape with index index"""
        self.open_shapefile()
        shape = self.shapefile.read_object(index)

        if self.shapetype == SHAPETYPE_POINT:
            points = shape.vertices()
        else:
            #for poly in shape.vertices():
            poly = shape.vertices()[0]
            points = []
            for x, y in poly:
                points.append((x, y))

        return Shape(points)

    def ShapesInRegion(self, box):
        """Return the ids of the shapes that overlap the box.

        Box is a tuple (left, bottom, right, top) in the coordinate
        system used by the layer's shapefile.
        """
        left, bottom, right, top = box
        return self.shapetree.find_shapes((left, bottom), (right, top))

    def SetProjection(self, projection):
        """Set the layer's projection"""
        self.projection = projection
        self.changed(LAYER_PROJECTION_CHANGED, self)

    def GetClassification(self):
        return self.__classification

    def SetClassification(self, clazz):
        """Set the classification to 'clazz'

        If 'clazz' is None a default classification is created
        """

        if clazz is None:
            self.__classification = classification.Classification()
        else:
 
            # prevent infinite recursion when calling SetLayer()
            if clazz == self.__classification:
                return

            self.__classification = clazz
            self.__classification.SetLayer(self)

        self.changed(LAYER_LEGEND_CHANGED, self)

    def ClassChanged(self):
        """Called from the classification object when it has changed."""
        self.changed(LAYER_LEGEND_CHANGED, self)
 
    def TreeInfo(self):
        items = []

        if self.Visible():
            items.append(_("Shown"))
        else:
            items.append(_("Hidden"))
        items.append(_("Shapes: %d") % self.NumShapes())

        bbox = self.LatLongBoundingBox()
        if bbox is not None:
            items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
        else:
            items.append(_("Extent (lat-lon):"))
        items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])

        items.append(self.__classification)

        return (_("Layer '%s'") % self.Title(), items)

1	bh	73	# Copyright (c) 2001, 2002 by Intevation GmbH
2	bh	6	# Authors:
3			# Bernhard Herzog <[email protected]>
4	jonathan	412	# Jonathan Coles <[email protected]>
5	bh	6	#
6			# This program is free software under the GPL (>=v2)
7			# Read the file COPYING coming with Thuban for details.
8
9			__version__ = "$Revision$"
10
11	bh	276	import os
12	bh	171	from math import log, ceil
13
14	jan	374	from Thuban import _
15
16	bh	143	import shapelib, shptree
17	bh	6
18			from messages import LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \
19			LAYER_VISIBILITY_CHANGED
20
21			from color import Color
22
23	jonathan	437	import classification
24	bh	6
25			from table import Table
26
27			from base import TitledObject, Modifiable
28
29			class Shape:
30
31			"""Represent one shape"""
32
33			def __init__(self, points):
34			self.points = points
35			#self.compute_bbox()
36
37			def compute_bbox(self):
38			xs = []
39			ys = []
40			for x, y in self.points:
41			xs.append(x)
42			ys.append(y)
43			self.llx = min(xs)
44			self.lly = min(ys)
45			self.urx = max(xs)
46			self.ury = max(ys)
47
48			def Points(self):
49			return self.points
50
51
52
53			# Shape type constants
54			SHAPETYPE_POLYGON = "polygon"
55			SHAPETYPE_ARC = "arc"
56			SHAPETYPE_POINT = "point"
57
58			# mapping from shapelib shapetype constants to our constants
59			shapelib_shapetypes = {shapelib.SHPT_POLYGON: SHAPETYPE_POLYGON,
60			shapelib.SHPT_ARC: SHAPETYPE_ARC,
61			shapelib.SHPT_POINT: SHAPETYPE_POINT}
62
63			shapetype_names = {SHAPETYPE_POINT: "Point",
64			SHAPETYPE_ARC: "Arc",
65			SHAPETYPE_POLYGON: "Polygon"}
66
67			class BaseLayer(TitledObject, Modifiable):
68
69			"""Base class for the layers."""
70
71			def __init__(self, title, visible = 1):
72			"""Initialize the layer.
73
74			title -- the title
75			visible -- boolean. If true the layer is visible.
76			"""
77			TitledObject.__init__(self, title)
78			Modifiable.__init__(self)
79			self.visible = visible
80
81			def Visible(self):
82			"""Return true if layer is visible"""
83			return self.visible
84
85			def SetVisible(self, visible):
86			"""Set the layer's visibility."""
87			self.visible = visible
88			self.issue(LAYER_VISIBILITY_CHANGED, self)
89	bh	276
90
91	bh	6	class Layer(BaseLayer):
92
93			"""Represent the information of one geodata file (currently a shapefile)
94
95			All children of the layer have the same type.
96
97			A layer has fill and stroke colors. Colors should be instances of
98			Color. They can also be None, indicating no fill or no stroke.
99
100			The layer objects send the following events, all of which have the
101			layer object as parameter:
102
103			TITLE_CHANGED -- The title has changed.
104			LAYER_PROJECTION_CHANGED -- the projection has changed.
105			LAYER_LEGEND_CHANGED -- the fill or stroke attributes have changed
106
107			"""
108
109			def __init__(self, title, filename, projection = None,
110	jonathan	412	fill = Color.None,
111			stroke = Color.Black,
112	jonathan	464	lineWidth = 1,
113	jonathan	412	visible = 1):
114	bh	6	"""Initialize the layer.
115
116			title -- the title
117			filename -- the name of the shapefile
118			projection -- the projection object. Its Inverse method is
119			assumed to map the layer's coordinates to lat/long
120			coordinates
121	jonathan	464	fill -- the fill color or Color.None if the shapes are not filled
122			stroke -- the stroke color or Color.None if the shapes are not stroked
123	bh	6	visible -- boolean. If true the layer is visible.
124
125			colors are expected to be instances of Color class
126			"""
127			BaseLayer.__init__(self, title, visible = visible)
128	bh	276
129			# Make the filename absolute. The filename will be
130			# interpreted relative to that anyway, but when saving a
131			# session we need to compare absolute paths and it's usually
132			# safer to always work with absolute paths.
133			self.filename = os.path.abspath(filename)
134
135	bh	6	self.projection = projection
136			self.shapefile = None
137	bh	143	self.shapetree = None
138	bh	21	self.open_shapefile()
139	bh	6	# shapetable is the table associated with the shapefile, while
140			# table is the default table used to look up attributes for
141			# display
142			self.shapetable = Table(filename)
143			self.table = self.shapetable
144
145	jonathan	481	#
146			# this is really important so that when the classification class
147			# tries to set its parent layer the variable will exist
148			#
149			self.__classification = None
150
151	jonathan	492
152			self.SetClassification(None)
153
154	jonathan	464	self.__classification.SetDefaultLineColor(stroke)
155			self.__classification.SetDefaultLineWidth(lineWidth)
156	jonathan	412	self.__classification.SetDefaultFill(fill)
157	jonathan	492	self.__classification.SetLayer(self)
158	jonathan	364
159	jonathan	389	self.UnsetModified()
160
161	bh	6	def open_shapefile(self):
162			if self.shapefile is None:
163			self.shapefile = shapelib.ShapeFile(self.filename)
164			numshapes, shapetype, mins, maxs = self.shapefile.info()
165			self.numshapes = numshapes
166			self.shapetype = shapelib_shapetypes[shapetype]
167
168	bh	179	# if there are shapes, set the bbox accordinly. Otherwise
169			# set it to None.
170			if self.numshapes:
171			self.bbox = mins[:2] + maxs[:2]
172			else:
173			self.bbox = None
174
175	bh	171	# estimate a good depth for the quad tree. Each depth
176			# multiplies the number of nodes by four, therefore we
177			# basically take the base 4 logarithm of the number of
178			# shapes.
179			if self.numshapes < 4:
180			maxdepth = 1
181			else:
182			maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))
183
184			self.shapetree = shptree.SHPTree(self.shapefile.cobject(), 2,
185			maxdepth)
186
187	bh	258	def Destroy(self):
188	bh	260	BaseLayer.Destroy(self)
189	bh	258	if self.shapefile is not None:
190			self.shapefile.close()
191			self.shapefile = None
192			self.shapetree = None
193			self.table.Destroy()
194
195	bh	6	def BoundingBox(self):
196	bh	179	"""Return the layer's bounding box in the intrinsic coordinate system.
197
198			If the layer has no shapes, return None.
199			"""
200			# The bbox will be set by open_shapefile just as we need it
201			# here.
202	bh	6	self.open_shapefile()
203			return self.bbox
204
205			def LatLongBoundingBox(self):
206	bh	179	"""Return the layer's bounding box in lat/long coordinates.
207	bh	6
208	bh	179	Return None, if the layer doesn't contain any shapes.
209			"""
210			bbox = self.BoundingBox()
211			if bbox is not None:
212			llx, lly, urx, ury = bbox
213			if self.projection is not None:
214			llx, lly = self.projection.Inverse(llx, lly)
215			urx, ury = self.projection.Inverse(urx, ury)
216			return llx, lly, urx, ury
217			else:
218			return None
219
220	jonathan	464	def GetFieldType(self, fieldName):
221			self.open_shapefile()
222			info = self.table.field_info_by_name(fieldName)
223			if info is not None:
224			return info[0]
225			else:
226			return None
227
228	bh	6	def NumShapes(self):
229			"""Return the number of shapes in the layer"""
230			self.open_shapefile()
231			return self.numshapes
232
233			def ShapeType(self):
234			"""Return the type of the shapes in the layer.
235			This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.
236			"""
237			self.open_shapefile()
238			return self.shapetype
239
240			def Shape(self, index):
241			"""Return the shape with index index"""
242			self.open_shapefile()
243			shape = self.shapefile.read_object(index)
244	jonathan	364
245	bh	6	if self.shapetype == SHAPETYPE_POINT:
246			points = shape.vertices()
247			else:
248			#for poly in shape.vertices():
249			poly = shape.vertices()[0]
250			points = []
251			for x, y in poly:
252	bh	82	points.append((x, y))
253	jonathan	364
254	bh	6	return Shape(points)
255
256	bh	143	def ShapesInRegion(self, box):
257			"""Return the ids of the shapes that overlap the box.
258
259			Box is a tuple (left, bottom, right, top) in the coordinate
260			system used by the layer's shapefile.
261			"""
262			left, bottom, right, top = box
263	bh	147	return self.shapetree.find_shapes((left, bottom), (right, top))
264	bh	143
265	bh	6	def SetProjection(self, projection):
266			"""Set the layer's projection"""
267			self.projection = projection
268			self.changed(LAYER_PROJECTION_CHANGED, self)
269
270	jonathan	412	def GetClassification(self):
271			return self.__classification
272
273			def SetClassification(self, clazz):
274	jonathan	492	"""Set the classification to 'clazz'
275	jonathan	481
276	jonathan	492	If 'clazz' is None a default classification is created
277			"""
278	jonathan	481
279	jonathan	492	if clazz is None:
280			self.__classification = classification.Classification()
281			else:
282
283			# prevent infinite recursion when calling SetLayer()
284			if clazz == self.__classification:
285			return
286
287			self.__classification = clazz
288			self.__classification.SetLayer(self)
289
290	jonathan	412	self.changed(LAYER_LEGEND_CHANGED, self)
291
292	jonathan	492	def ClassChanged(self):
293			"""Called from the classification object when it has changed."""
294			self.changed(LAYER_LEGEND_CHANGED, self)
295
296	bh	217	def TreeInfo(self):
297			items = []
298
299			if self.Visible():
300	jan	374	items.append(_("Shown"))
301	bh	217	else:
302	jan	374	items.append(_("Hidden"))
303			items.append(_("Shapes: %d") % self.NumShapes())
304	bh	217
305			bbox = self.LatLongBoundingBox()
306			if bbox is not None:
307	jan	374	items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
308	bh	217	else:
309	jan	374	items.append(_("Extent (lat-lon):"))
310			items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])
311	bh	217
312	jonathan	412	items.append(self.__classification)
313	bh	217
314	jan	374	return (_("Layer '%s'") % self.Title(), items)
315	jonathan	382
Name	Value
svn:eol-style	native
svn:keywords	Author Date Id Revision